With youth, talent and two All-Stars coming back, can anything stop Celtics' ascent next season?

That’s the question, isn’t it? Has there been a team in NBA history that can pivot from a crushing conference finals loss to “Holy crap, we could be a title favorite next season” quicker than the Boston Celtics? The Celtics came up a win shy of being the first team to oust LeBron James in the conference playoffs in eight years, and next season will reintroduce two All-Star, 20-plus-point scorers into the lineup.

Brad Stevens wasn’t interested in entertaining questions about next season after Sunday’s Game 7 defeat. “I think we’ll have plenty of time to talk about next year,” said the Celtics coach. “But I don’t want to take away right now from what those guys that were in that room just did.” On Monday, the players weren’t eager to talk about the future either. Sunday was a sleepless night for the Celtics. “It sucks to come up short,” Terry Rozier said. Boston entered Game 7 with a 10-0 home record during the playoffs, held a halftime lead and then watched James take over down the stretch.

“It’s humbling to get to a certain point and lose,” Jaylen Brown said. “It makes you want to get better. It makes me realize how much better I need to get. Come back twice as good.”

And that’s the thing: Brown, 21, who more than doubled his scoring average this season, raised his 3-point shooting percentage more than five points and shot 46.5 percent from the floor, is going to get better. Jayson Tatum, 20, who declared the offseason to be about adding muscle to his slender, 205-pound frame, will too. Rozier, 24, said he plans to reach out to other point guards this summer to further his development as a playmaker. Defenses won’t be able to key on any of them as much, not with Kyrie Irving and Gordon Hayward in the mix.

Despite coming up short in Game 7 Sunday night, Jayson Tatum and the Celtics are in great position for the future. (Getty)

“I get a kick out of the fact that everywhere I go people think we don’t need Kyrie and Gordon Hayward,” Celtics GM Danny Ainge said. “I have a much longer memory, and I remember how great those guys were and what an effort it took to get them. I also remember how great they are, and how young they are still. We need them, absolutely we need them. If this playoff run didn’t show that, I don’t know what does. We were able to win some games, we were able to fight some battles, but we are much, much better with Kyrie and Gordon.”

So what can derail this Boston team? There are injuries. Hayward isn’t close to full strength. Ainge said Hayward was back on the court, playing one-on-one, but was still months away from being game ready. Irving was conspicuously absent from the Celtics’ sideline in Game 7. Turns out he had a procedure to relieve a deviated septum before Game 3 and was recovering. But team officials say Irving’s recovery from knee surgery has been smooth, and he is expected to be at full strength by training camp.

There’s complacency, though it’s hard to see the Celtics feeling entitled to anything. “You can’t assume that you will be in this position,” Al Horford said. “Our message from the start of training camp next year is we need to build it back up. We’re not going to start in this position. It’s not easy to get to this point. We just need to get back to work.” On Tuesday, Aron Baynes — the only Celtics player with a championship — reminded his teammates of his time in San Antonio, when the Spurs, on the cusp of knocking off James’ Heat in Game 6 of the 2013 NBA Finals, suffered a stunning series defeat. That loss fueled the Spurs the next season; this loss, Baynes said, should motivate Boston, too.

“This is going to help shape the rest of their careers,” Horford said. “I hope they are able to take away the intensity and the commitment of doing those little things that make us successful.”

There’s ego, and this is a legitimate concern. Boston has five starting spots and seven players with legitimate claims to them. Rozier defused any point guard controversy by declaring the job Irving’s — “He’s the starter, he’s our starter, he’s our starting point guard,” Rozier said — and said that the competition in practice will benefit the team.

“Obviously, Kyrie Irving is Kyrie Irving,” Rozier said. “I’ll never try to step on [his] toes. But I’m going to challenge him every day. It’s going to be a lot of fun. I’m going to pick his brain every day, just like I did as much as I could this year. I’m looking to make him work, and I know he is going to make me work.”

But minutes will be at a premium, and while Boston can trot out its own undersized death lineup (Irving/Hayward/Brown/Tatum/Horford will be a matchup nightmare), realistically there will be three players (Hayward, Tatum and Brown) competing for two starting spots, and all three can make a case that they have earned a spot.

Said Ainge, “Guys have proven they are NBA starting material in this league.”

There are expectations, and there will be plenty. The Celtics aren’t the surprising playoff team, the upstart No. 1 seed or the feisty overachievers anymore. They are frontrunners, and that comes with pressure. Pressure on ownership, which has stepped up before — Boston effectively has three max-contract players — but will have some tough financial decisions to make. Boston’s roster will get pricey in the coming years, which could impact decisions on Marcus Smart — a restricted free agent expected to command $10 million (or more) per season — and Baynes.

“We know that in Boston, our ownership group has been fantastic,” Ainge said. “They have been very willing to pay for teams that have a chance. The way that our team played this year, the hope [is] that will make it easier for them to step forward and realize the potential of this team, and be willing to pay the money we need to be as good as we can.”

There will be pressure on Stevens, who will have a buffet of options to choose from and the responsibility to find minutes and shots for all of them. Stevens’ message to his players after Game 7: pain is part of the path. Stevens will navigate that path for the Celtics next season, and for the first time in his tenure it will be expected to end in a championship.

Are these problems? Good ones, for sure. Boston’s window opens next season, and it could be years before it closes. As the Celtics addressed the media one final time on Monday, a recurring theme surfaced: We can’t wait until next season.

“It’s going to be very competitive,” Tatum said. “We have a lot of talent, with whoever comes back. I’m looking forward to it. It’s going to be a lot of fun.”